The National Dispatching Center (NDC) of the Electricity System Operator is acting as an operator of the national power transmission system and performs the functions of centralized real time dispatching, control and supervision of the electrical power system (EPS). Its main assignment is to guarantee the reliable and efficient operation of the Bulgarian EPS and its synchronous operation with the partners in the UCTE. NDC organize also the electricity market. There are four Regional Dispatching Centers (RDC) covering the territory of Bulgaria.